They spent 11 months digging into allegations of collusion with Russia, obstruction of justice, money laundering and assorted other misdeeds.

And now comes Mueller time.

The special counsel had already racked up guilty pleas from top advisers to President Trump and indictments of Russian trolls and the president’s former campaign chairman. But events of this week show that Robert Mueller’s Russia probe, long a theoretical threat to the Trump presidency, is getting real, and possibly more visible.

On Monday night, court filings by Mueller’s team indicated that Deputy Attorney General Rod Rosenstein had authorized Mueller last summer to investigate whether Paul Manafort, Trump’s former campaign chairman, “committed a crime or crimes by colluding with Russian government officials” over the 2016 election.

On Tuesday night, The Washington Post reported that Mueller informed Trump’s lawyers last month that while he is not a criminal target, he is a subject of the investigation, which means his conduct is being examined.

In between, on Tuesday morning, a young Dutchman entered the federal courthouse on Third Street NW and earned the dubious distinction of being the first person to be sent to prison in the Mueller probe.

Alex van der Zwaan, son-in-law of a Russian oligarch, business associate of Manafort and soon-to-be-sentenced felon, stepped from a Cadillac Escalade and into a multilingual pack of 18 cameras and activist Bill Christeson, who shouted, “Lock him up!”

“Charming guy,” the defendant said with a smile and slight accent as he joined his friends in the court’s security line.

And now he’s going to meet several other charming guys – during his 30-day stay in prison. It was a symbolic sentence for a man who, prosecutors said, had “a moral compass that was off-kilter” and repeatedly lied to investigators about his dealings with Manafort and business partner Rick Gates, also a Trump adviser. He avoided a longer sentence because he ultimately came clean.

Van der Zwaan, 33, who worked for the law firm Skadden, Arps, Slate, Meagher & Flom while also trying to ingratiate himself with Manafort and Gates in Ukraine, cut an unsympathetic figure. If he is remembered for anything other than being first in the pokey, it will likely be for his nonchalance in the courtroom.

Van der Zwaan, with slicked hair, a tightly tailored blue blazer with brass buttons, French cuffs, a spread collar and a perfect half-inch of pocket square showing, offered a perfunctory presentencing statement (“I apologize to the court … I apologize to my wife and family”). The judge noted that she had received written statements from the defendant’s parents, best friend, pregnant wife and wife’s doctor – but nothing from the defendant himself. At this, van der Zwaan looked reproachfully at his lawyer.

His remorse is “somewhat muted, to say the least,” observed the judge, Amy Berman Jackson.

Van der Zwaan’s bit role as the first jailbird of the Mueller probe gives some clues about where else it may go. He’s the son-in-law of German Khan, who is worth more than $9 billion and is an owner of a Russian bank that figured prominently in the “dossier” about alleged Russia-Trump collusion. Van der Zwaan also knew that Gates had been in contact during Trump’s presidential campaign with a person tied to Russian intelligence services.

Wherever Mueller is heading, it seems to be unnerving the president, who tends to become more erratic at pivotal moments in the probe. Trump has been stirring up a trade war, stoking anti-immigrant sentiments and calling out his predecessor as “Cheatin’ Obama.”

I’d be on edge if I were in Trump’s shoes, too. Mueller’s Men – there were 11 lawyers and investigators, none female, in court for the van der Zwaan sentencing – aren’t a cuddly bunch. Prosecutor Andrew Weissmann said that the defendant had “a clear lack of morality” and came clean only because he was “caught red-handed” about his lies.

Defense lawyer William Schwartz made an improbable plea of poverty, saying that the defendant is “not wealthy” and dismissing references “to his father-in-law as an oligarch, as if that has some bearing.”

Jackson was unmoved. She told van der Zwaan that he “may self-deport” home to Europe after his month in the pen.

On the sidewalk outside the court, the newly sentenced van der Zwaan, no longer smiling, was again accosted by the activist Christeson. “Hey, Alex – it’s Mueller time!” he shouted, invoking the old beer ad. “Congratulations.”

The Escalade pulled away. “One down, 30 to go,” a news photographer joked.

Thirty may be a stretch. But many others will soon follow the lying Dutchman.

Dana Milbank is a columnist for The Washington Post. He can be contacted at:

dana.milbank@washpost.com